Due to the complexity of electric power systems nowadays electrical faults occur frequently in all parts of the power system. As producers and users of Electrical Energy, you must increase your awareness of present and future power system protection. System integrity depends on a well-conceived and properly implemented protection philosophy. It is important to learn how to implement a system where equipment or line removal and system restoration occur quickly and reliably. To do this, it is essential to understand the power system protection and how present mechanical and microprocessor-based relaying systems function, how they communicate, how their performance can be analyzed and what are the future challenges and how connect with the instrument transformer (CT & VT ) also the tripping signal to the circuit breaker.